settings: Wildcard 'ALLOWED_HOSTS' settings

settings: Wildcard 'ALLOWED_HOSTS' settings

Django 1.10.3, 1.9.11 and 1.8.16 changed default behavior for
ALLOWED_HOSTS to prevent DNS rebinding attacks [1]. Unfortunately this
also means we can't access the development Docker or Vagrant installs
by IP address. Sidestep the issue by wildcarding the 'ALLOWED_HOSTS'
setting for development, thus allowing connections from any IP.

[1] https://docs.djangoproject.com/en/1.10/ref/settings/#allowed-hosts

Signed-off-by: Stephen Finucane <stephen@that.guru>
Reviewed-by: Daniel Axtens <dja@axtens.net>